/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * <BR><BR>
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * <BR><BR>
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * <BR><BR>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * <BR><BR>
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * <BR><BR>
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *########################################################################
 */
package org.greenstone.gatherer.gui;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import org.greenstone.gatherer.Dictionary;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.file.FileAssociationManager;
import org.greenstone.gatherer.gui.GComboBox;
import org.greenstone.gatherer.gui.ModalDialog;
import org.greenstone.gatherer.gui.SimpleMenuBar;
import org.greenstone.gatherer.util.Utility;
import org.outerj.pollo.util.*;

/** The file association allows the entry of new file associations and the modification of existing ones. This is done via a list of known extensions, and two fields to fill out relevant details. 
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.3
 */
public class FileAssociationDialog
    extends ModalDialog {
    /** <i>true</i> iff this addition action been cancelled by the user. */
    private boolean cancelled = false;
    /** <i>true</i> iff we should ignore any current changes to the extension list. */
    private boolean ignore = false;
    /** <i>true</i> iff the extension has not changed recently, but the command has. */
    private boolean save_required = false;
    /** A reference to ourselves so that our inner classes can dispose of us. */
    private FileAssociationDialog self;
    /** A reference to the manager in charge of storing all the file association information. */
    private FileAssociationManager manager;
    /** The button used to open a file browser for simplier executable selection. */
    private JButton browse;
    /** The button used to cancel this dialog without commiting any changes. */
    private JButton cancel;
    /** The button used to hide this dialog after updating or adding file associations as necessary. */
    private JButton ok;
    /** The combobox used to select what extension you wish to change. */
    private GComboBox extension;
    /** A field for entering the command string. */
    private JTextField command;
    /** The extension last chosen from the combobox. This way we can determine if the extension has been modified by the user. */
    private String previous_extension;
    /** The default size of a label. */
    static final private Dimension LABEL_SIZE = new Dimension(150, 25);
    /** The default size for the dialog. */
    static final private Dimension SIZE = new Dimension(600, 270);

    /** Create a new file association dialog.
     * @param manager A reference to the <strong>FileAssociationManager</strong> so we can determine what extensions are already associated.
     * @see org.greenstone.gatherer.Configuration
     * @see org.greenstone.gatherer.gui.Coloring
     */
    public FileAssociationDialog(FileAssociationManager manager) {
	super(Gatherer.g_man);
	this.manager = manager;
	this.self = this;
		  
	// Creation
	setModal(true);
	setSize(SIZE);
	setJMenuBar(new SimpleMenuBar("fileassociations"));
	Dictionary.setText(this, "FileAssociationDialog.Title");

	JPanel content_pane = (JPanel) getContentPane();
	content_pane.setBackground(Gatherer.config.getColor("coloring.collection_heading_background", false));
	JPanel control_pane = new JPanel();

	JTextArea instructions_area = new JTextArea();
	instructions_area.setEditable(false);
	instructions_area.setLineWrap(true);
	instructions_area.setRows(5);
	instructions_area.setWrapStyleWord(true);
	Dictionary.setText(instructions_area, "FileAssociationDialog.Instructions");

	JPanel extension_pane = new JPanel();
	extension_pane.setOpaque(false);
	JLabel extension_label = new JLabel();
	extension_label.setPreferredSize(LABEL_SIZE);
	Dictionary.setText(extension_label, "FileAssociationDialog.Extension");

	extension = new GComboBox();
	extension.setEditable(true);
	extension.setPreferredSize(LABEL_SIZE);
	for(int i = 0; i < manager.size(); i++) {
	    extension.add(manager.getExtension(i));
	}
	Dictionary.setTooltip(extension, "FileAssociationDialog.Extension_Tooltip");

	JPanel command_pane = new JPanel();
	command_pane.setOpaque(false);
	JLabel command_label = new JLabel();
	command_label.setPreferredSize(LABEL_SIZE);
	Dictionary.setText(command_label, "FileAssociationDialog.Command");
	JPanel inner_pane = new JPanel();
	inner_pane.setOpaque(false);
	command = new JTextField();
	command.setBackground(Gatherer.config.getColor("coloring.collection_tree_background", false));
	command.setSelectionColor(Gatherer.config.getColor("coloring.collection_selection_background", false));
	command.setSelectedTextColor(Gatherer.config.getColor("coloring.collection_selection_foreground", false));
	if(extension.count() > 0) {
	    command.setText(manager.getCommandString((String)extension.get(0)));
	}
	Dictionary.setTooltip(command, "FileAssociationDialog.Command_Tooltip");

	browse = new JButton();
	browse.setBackground(Gatherer.config.getColor("coloring.button_background", false));
	browse.setMnemonic(KeyEvent.VK_B);
	browse.setPreferredSize(LABEL_SIZE);
	Dictionary.setBoth(browse, "FileAssociationDialog.Browse", "FileAssociationDialog.Browse_Tooltip");

	JPanel button_pane = new JPanel();
	button_pane.setOpaque(false);
	ok = new JButton();
	ok.setBackground(Gatherer.config.getColor("coloring.button_background", false));
	ok.setMnemonic(KeyEvent.VK_O);
	Dictionary.setBoth(ok, "General.OK", "General.OK_Tooltip");
	cancel = new JButton();
	cancel.setBackground(Gatherer.config.getColor("coloring.button_background", false));
	cancel.setMnemonic(KeyEvent.VK_C);
	Dictionary.setBoth(cancel, "General.Cancel", "General.Pure_Cancel_Tooltip");

	// Connection
	browse.addActionListener(new BrowseListener());
	cancel.addActionListener(new CancelListener());
	ok.addActionListener(new OKListener());
	extension.addActionListener(new ExtensionListener());
	command.getDocument().addDocumentListener(new CommandListener());

	// Layout
	extension_pane.setBorder(BorderFactory.createEmptyBorder(5,0,0,0));
	extension_pane.setLayout(new BorderLayout());
	extension_pane.add(extension_label, BorderLayout.WEST);
	extension_pane.add(extension, BorderLayout.EAST);

	inner_pane.setLayout(new BorderLayout());
	inner_pane.add(command, BorderLayout.CENTER);
	inner_pane.add(browse, BorderLayout.EAST);

	command_pane.setBorder(BorderFactory.createEmptyBorder(5,0,5,0));
	command_pane.setLayout(new GridLayout(2,1));
	command_pane.add(command_label);
	command_pane.add(inner_pane);

	control_pane.setLayout(new BorderLayout());
	control_pane.add(extension_pane, BorderLayout.NORTH);
	control_pane.add(command_pane, BorderLayout.CENTER);

	button_pane.setLayout(new GridLayout(1,2,2,2));
	button_pane.add(ok);
	button_pane.add(cancel);
		  
	content_pane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
	content_pane.setLayout(new BorderLayout());
	content_pane.add(new JScrollPane(instructions_area), BorderLayout.NORTH);
	content_pane.add(control_pane, BorderLayout.CENTER);
	content_pane.add(button_pane, BorderLayout.SOUTH);

	Dimension screen_size = Gatherer.config.screen_size;
	setLocation((screen_size.width - SIZE.width) / 2, (screen_size.height - SIZE.height) / 2);
    }
    /** Destructor to ensure dialog gets garbage collected. */
    public void destroy() {
	self = null;
	manager = null;
	browse = null;
	cancel = null;
	ok = null;
	extension = null;
	command = null;
	previous_extension = null;
    }

    /** Redisplay the dialog, ensuring that the details (or lack thereof) for a certain extension is apparent. In fact if an extension is provided force the user to add it or cancel.
     * @param new_extension The extension code as a <strong>String</strong>.
     */
    public String display(String new_extension) {
	if(new_extension != null) {
	    Dictionary.setBoth(ok, "FileAssociationDialog.Add", "FileAssociationDialog.Add_Tooltip");
	    int index = extension.add(new_extension);
	    extension.setSelectedIndex(index);
	    extension.setEnabled(false);
	}
	else {
	    Dictionary.setBoth(ok, "General.OK", "General.OK_Tooltip");
	    extension.setEnabled(true);
	}
	setVisible(true);
	if(save_required) {
	    setCommand((String)extension.getSelectedItem(), (String)command.getText(), true);
	    save_required = false;
	}
	if(!cancelled) {
	    return setCommand((String)extension.getSelectedItem(), (String)command.getText(), false);
	}
	else {
	    return null;
	}
    }

    private String setCommand(String extension, String command, boolean process) {
	if(command.indexOf(FileAssociationManager.FILENAME_ARG) == -1) {
	    command = command + " " + FileAssociationManager.FILENAME_ARG;
	}
	if(process) {
	    manager.setCommand(extension, command);
	}
	return command;
    }

    /** Whenever the user clicks the browse button, we should open up a file browser to allow them to select an executable file from somewhere in the file system. */
    private class BrowseListener 
	implements ActionListener {
	/** Open up a simple JFileChooser when the user clicks the button. 
	 * @param event An <strong>ActionEvent</strong> containing information about the event.
	 */
	public void actionPerformed(ActionEvent event) {
	    JFileChooser chooser = new JFileChooser(new File(Utility.BASE_DIR));
	    chooser.setDialogTitle(Dictionary.newget("FileAssociationDialog.Browse_Title"));
	    chooser.setFileFilter(new ExtensionFileFilter(".bat", Dictionary.newget("FileAssociationDialog.Batch_File")));
	    chooser.setFileFilter(new ExtensionFileFilter(".com", Dictionary.newget("FileAssociationDialog.Command_File")));
	    chooser.setFileFilter(new ExtensionFileFilter(".exe", Dictionary.newget("FileAssociationDialog.Executable_File")));
	    chooser.setAcceptAllFileFilterUsed(true);
	    int return_val = chooser.showOpenDialog(null);
	    if(return_val == JFileChooser.APPROVE_OPTION) {
		command.setText(chooser.getSelectedFile().getAbsolutePath());
		save_required = true;
	    }
	}
    }

    /** Listens for actions apon the cancel button, and if detected disposes of the dialog without saving changes. */
    private class CancelListener
	implements ActionListener {
	/** Listens for actions apon the cancel button, and if detected disposes of the dialog without saving changes. 
	 * @param event An <strong>ActionEvent</strong> containing further information about the action.
			*/
	public void actionPerformed(ActionEvent event) {
	    cancelled = true;
	    save_required = false;
	    self.dispose();
	}
    }

    /** If any changes occur to the command field, mark it as needing saving before we can change extensions, or dispose of this dialog (other than cancelling. */
    private class CommandListener
	implements DocumentListener {
	/** Gives notification that an attribute or set of attributes changed. */
	public void changedUpdate(DocumentEvent e) {
	    save_required = !ignore && true;
	}
	/** Gives notification that there was an insert into the document. */
	public void insertUpdate(DocumentEvent e) {
	    save_required = !ignore && true;
	}
          
	/** Gives notification that a portion of the document has been removed. */
	public void removeUpdate(DocumentEvent e) {
	    save_required = !ignore && true;
	}
    }

    /** Whenever the user selects an extension, we should fill out the command field with whatever value has been previously entered for the command (if any). */
    private class ExtensionListener
	implements ActionListener {
	/** This method is called whenever the selection in the extension list changes, so that we can save any old details, then load up the information for the new selection.
	 * @param event An <strong>ItemEvent</strong> encompassing everything you ever wanted to know about the list selectio, but were afraid to ask.
	 * @see org.greenstone.gatherer.file.FileAssociationManager
	 */
	public void actionPerformed(ActionEvent event) {
	    String ext = (String) extension.getSelectedItem();
	    if(!ignore && ext != null && ext.length() > 0) {
		ignore = true;
		// Save the previous extension if necessary
		if(save_required && previous_extension != null) {
		    setCommand(previous_extension, command.getText(), true);
		    save_required = false;
		}
		command.setText(manager.getCommandString(ext));
		previous_extension = ext;
		ignore = false;
	    }
	}
    }

    /** Listen for clicks on the ok button, and dispose when detected. */
    private class OKListener
	implements ActionListener {
	/** When a click on OK is detected, save the current information, then dispose.
	 * @param event An <strong>ActionEvent</strong> with details about the button press.
			*/
	public void actionPerformed(ActionEvent event) {
	    if(save_required) {
		setCommand(extension.getSelectedItem().toString(), command.getText(), true);
		save_required = false;
	    }
	    self.dispose();
	}
    }
}